Micromanipulation and characterization of objects ranging in size from atomic to micrometer dimensions has become one of the central features of modern science. Optical trapping methods are known for manipulating latex micron-sized balls attached to objects of biological interest at room temperature. In addition, systems based on carbon nanotubes have been utilized for physical tweezing of micro-objects.
Miniaturizing mechanical, optical, magnetic, and electronic components is part of a major effort in development and use of micro- and nano-scale devices and systems. For example, there has been a significant amount of micro-electromechanical systems (MEMS) research with the goal of reducing the size of systems into sub-millimeter dimensions.
As part of the development and operation of these miniaturized systems, it is highly desired to provide methods and systems for manipulating very small (micro- or nano-scale, for example) particles in various environments, including air, vacuum, or fluid.
As an example, there exists a specific interest in the manipulation of magnetic objects. Magnetic tweezers have found wide uses in biological applications, such as in the investigations of the physical properties of the cytoplasm, mechanical properties of cell surfaces, and elasticity and transport of single DNA molecules. For cell studies, most of these techniques rely on the micromanipulation of a magnetic particle positioned inside a cell wall or bound on the surface of a cell, while the single molecule investigations involve linking the magnetic particle on one end of the molecule strand. In all of these studies, micromanipulation is performed with a device consisting of permanent or soft coil-wound magnets with macroscopic dimensions. Typical forces available through these techniques are in the range of 0.1-10 pN.